The present invention relates to the use of mesomorphic phases of edible surfactants, in the first place for the structuring of foodstuff and to finished or ready to eat surfactants containing said mesomorphic phases.
According to the general prior art the structuring of foodstuffs can be accomplished in various ways. Two main routes can be distinguished:
(1) the structuring by biopolymers such as proteins and carbohydrates, and
(2) the structuring by xe2x80x9cparticlesxe2x80x9d in the widest sense.
In the former case polymeric molecules cross-link to form a tangled, interconnected molecular network in water. In those systems the presence of junction zones or entanglements leads to gel formation and the enclosure of water. Examples of those polymeric substances are starch in puddings, gelatin in deserts and in the water phase of fat spreads, pectin in jams, carrageenin in desserts and in the water phase of fat spreads, and many others.
In the second case entities such as air cells, water droplets, fat droplets, crystals, starch granules or casein micelles are dispersed into the food system. Interaction forces between such particles determine the consistency and the physical stability of the food products. Many food systems fall into this category. In yoghurt aggregated protein particles form a network of protein strands. In mayonnaise an xe2x80x9cinterconnectedxe2x80x9d structure of oil droplets is responsible for its consistency. In a shortening fat crystals form an interconnected network structure enclosing oil. In a margarine water droplets are dispersed into a continuous network structure of fat crystals and oil. So, this represents a dispersion of particles in a network of particles. Even more complicated structures are found in butter and ice cream. But in all those cases a build-up of structure from particles of particle networks can be distinguished, which is responsible for the consistency of the finished products.
The present invention provides a new way of structuring food products. The formation of mesomorphic phases of edible surfactant molecules and water can give rise to a firm texture and consistency. The use of this property of mesomorphic phases, to give consistency to products, is new to the food business. However, it should be noted hat this use may already be known in other areas such as cosmetics and pharmaceuticals.
This new way of product structuring may be described e.g. as a regular, molecular arrangement of surfactant molecules with intervening aqueous regions. For the purpose of the invention the term mesomorphic phase is intended to include all semi-ordered phases of water and edible surfactant materials. Examples of mesomorphic phases are cubic, hexagonal, alpha crystalline gel, beta-crystalline coagel and lamellar phases. Preferred mesomorphic phases for use in accordance with the invention are lyotropic phases; also preferred are lamellar phases. For the purpose of the present invention, the term lamellar phase refers to any system having a pattern of alternating bilayers of edible surfactants and water. Examples of lamellar phases are lamellar droplet phases, lamellar gel phases and lamellar phases containing extended parallel layers of surfactants and water.
In the lamellar phase surfactants, are believed to form a bilayer structure. It is believed that a bulk lamellar phase consists of stacks of bi-layer structures with an intervening aqueous phase. Products according to the present invention preferably comprise bulk regions of the lamellar phase whereas it has been suggested that known products of the prior art might contain boundary layers of this phase at interfaces, such as those found around oil-droplets in water-continuous fatty products.
The bulk lamellar phase may be formed by temperature cycling of a mixture of surfactant and water. In the crystalline state, the surfactant molecules are oriented with adjacent hydrophillic groups and the hydrophobic chains are parallel and densely packed. On contact with water and heating to the so-called xe2x80x98Krafftxe2x80x99 temperature it is believed that water penetrates between the adjacent xe2x80x98headxe2x80x99 groups to form a xe2x80x98liquid crystalxe2x80x99 structure. On cooling below the xe2x80x98Krafftxe2x80x99 temperature, the hydrophobic chains pack into a regular lattice, producing a one-dimensionally periodic xe2x80x98sandwichxe2x80x99 structure of alternating surfactant and aqueous layers.
As an example of the xe2x80x98gelxe2x80x99 structure obtained: for a mixture of water and a distilled monoglyceride made from fully hydrogenated lard, which has been cycled above the Krafft temperature, X-ray diffraction in the low-angle region reveals that the thickness of the monoglyceride layers is of the order of 50-60 Angstrom. As the proportion of water in the mixture in the system is increased the inter-planar spacing increases, as water is taken up between the monoglyceride layers. It will be realised that the fine structure of the mesomorphic phase, especially as regards the inter-planar spacing, will vary when different surfactants are used.
Another preferred mesomorphic phase according to the invention is a beta-crystalline coagel, which is believed to consist of small plate-like crystals having an average thickness of less than 1 fm or even less than 0.1 fm, said platelets being dispersed in an aqueous environment. This is a suspension of beta-crystalline emulsifier in water and is also known as a xe2x80x98hydratexe2x80x99. These coagels may be formed instead of an alpha crystalline gel phase under certain conditions, such as at acid pH. Both the above mentioned alpha gels and these hydrates are used extensively in the baking industry as crumb softening agents in wheat bread and as cake volume improvers, but it is believed that the structure of the mesomorphic phase is lost during product preparation and consequently that the finished foodstuff (be it bread or cake) does not contain bulk mesomorphic phase. In the context of the invention the coagel phase is considered a semi-ordered phase of water and edible surfactant (mesomorphic phase).
The presence of mesomorphic phases in food products may be detected by any method suitable for the detection of regular arrangements of surfactant materials. Suitable methods include for example NMR, Electron microscopy, Differential scanning calorimetry, light microscopy and X-ray diffraction.
Consequently, the present invention relates in the first place to the use of mesomorphic phases of edible surfactants as structuring agent. This structuring leads to many other useful applications, such as the use as fat replacer, foaming agent, egg white replacer, preservative, lubricating agent, consistency control agent, moisture retention agent and/or flavour release agent in foodstuff. In another aspect the invention relates to a finished foodstuff containing a mesomorphic phase of edible surfactant and less than 80% by weight of edible oil.
With respect to the use as fat replacer it should be noted that the present invention can provide edible compositions which have a reduced calorific contents as compared to normal foodstuffs. The present invention allows for the possibility of preparing foodstuffs with fat-like properties, but with the use according to the present invention containing essentially no fat at all or a very low amount of e.g. Less than 5 wt. %.
In recent years there have been several developments regarding so-called xe2x80x9cfat replacersxe2x80x9d. Such materials are intended to have as far as practical the functional and sensorial properties of fats, but to have a reduced calorie content and, where possible, health benefits as compared to fats. Much effort has been spent in the development of new materials which have a fatty functionality but are poorly adsorbed or non-digestible in the human gut.
Amongst such xe2x80x9cfat replacerxe2x80x9d materials are the sugar fatty acid esters, originally used as lubricants but now proposed for use in foods. The use of these sugar fatty acid esters as fat substitutes in margarines is suggested in EP-A-020 421 (Orphanos et al.: to the Procter and Gamble Company). Such margarines have a xe2x80x9cfattyxe2x80x9d phase which comprises one or more triglyceride fats and one or more fat-replacers mixed intimately or in mutual solution. Food products are also envisaged which contain no triglyceride but have a xe2x80x9cfatxe2x80x9d phase consisting essentially of one or more fat replacers. Further reference to edible fat replacers can be found in U.S. Pat. Nos. 4,005,195 and 4,005,196 and EP- A-223856, 236288 and 235836.
Other glyceride related lubricants, especially the so-called hindered polyols having no hydrogen at the beta-carbon, such as the pentaerythritols and related compounds have been proposed as fat replacers (see e.g. U.S. Pat. No. 4,927,659 to Nabisco Brands Inc.)
Fat replacers comprising proteinaceous materials have been described. However, it should be understood that because these materials are digestible, they do not have as marked a calorie reducing effect as the above mentioned fat replacers.
Few of these materials, such as the sucrose esters or hindered polyols have completely understood physiological effects. It is generally believed that further experimental work will be required before the physiological effects are fully determined. There remains a clear need for fat replacers which comprise materials of well-understood physiological effect.
It was now found that the mesomorphic phase of edible surfactants can be used as a fat-replacing food component with a fat-like functionality and a simple composition. The invention provides products having a fatty oral impression and a plastic rheology.
Their use as foaming agent stems from the capability of the mesomorphic phase to stabilize air cells. It leads to very stable foam structure with air cells surrounded by a continuous structure of mesomorphic phase. This allows for its use in all products where air stabilization is essential, such as low fat substitutes for whipped creams, ice-cream and creaming margarines.
Their use as egg white replacer results from the excellent foaming capability mentioned above. This allows for its use in all products where raw egg white is used for foaming, such as bavarois type of products and toppings. This is very important in view of the danger of salmonella infection of raw egg white.
Their use as preservative is ascribed to the enhanced microbial stability, caused by the limited size of the intervening water areas in mesomorphic phase systems, which hinders the outgrowth of microorganisms. For example, the size(spacing) of the intervening water layers in a mesomorphic phase which is a lamellar phase system containing 95% water is approximately 0.1 fm, which is far below the size (1 fm approx.) of the effective microorganisms.
Their use as lubricant is connected with the fatty functionality and the proper rheology of these materials, even at a high water content. Two aspects are considered to be important in this respect: the hydrophobicity of the aliphatic chains of the applied surfactant molecules and the induced flow properties, e.g. in case of the mesomorphic lamellar phase structure the bilayers of surfactant molecules are separated by layers of water and are thus free to slide in relation to each other with the water as the gliding plane.
Their use as consistency control agent is directly connected with the structuring capability. The desired rheological properties can be achieved by proper choice of experimental parameters, such as concentration of non-ionic- and ionic surfactant, shear, pH and electrolyte. An example of such an application is in the design of spoonable and pourable products.
Their use as moisture retention agent is connected with the enclosure of the water between aggregated surfactant molecules. The physical state of water in foods influence the physical, chemical and functional characteristics of foods and food components, by influencing the water transport and/or the water mobility and/or the water activity. The present invention allows the introduction of large amounts of xe2x80x9cimmobilizedxe2x80x9d water, which can be freed at a later stage.
Their use as flavour release agent is connected with the possibility to entrap flavours in the water phase c.q. the surfactant phase of the mesomorphic phase. The nature of the systems would lead to a controlled release of the applied flavours. Many controlled release delivery systems have been described in the literature, e.g. the use of liposomes. Those systems have to be prepared separately and have to be added to the foodstuff as an extra and only in a limited amount. The present invention allows the addition of flavour to the food system as such with proper retention of flavour components.
The mesomorphic phase and its method of preparation is known to food scientists. In the xe2x80x9cLipid Handbookxe2x80x9d of Gunstone, Harwood and Padley (Chapman and Hall, 1986) such phases are mentioned at page 227. Further detail may be found in xe2x80x9cFood emulsionsxe2x80x9d of S. Friberg (Marcel Decker, 1976 at page 82).
Such mesomorphic phases may advantageously be formed by heating a mixture containing the edible surfactant and water to a temperature above the Krafft temperature, followed by cooling.
It should be noted further that the above mentioned Lipid Handbook mentions at page 227 the use of mesomorphic phases of saturated, distilled monoglycerides as additives for processed potatoes or cake emulsions. However, this application is used for aerating bakery batters and enhanced complexing with amylose in non-finished starch based products. In the former application the aerating effect is ascribed to the better distribution of the monoglycerides in the batter system and in the latter application the monoglycerides form insoluble complexes with amylose, responsible for the crumb softening effect in bread and the texture improving effects on potato products and pasta foods. The emulsifiers are added to the bakery products before baking and to the potato products before final processing and consequently there is no mesomorphic phase in the finished products. The use of mesomorphic phases in such preparation methods for cake batters and processed potatoes are not embraced within the scope of the present invention.
In a preferred embodiment of the invention the mesomorphic phase is a lamellar gel phase. These phases are particularly preferred, because they can include a sensational amount of water, e.g. 98 or even 99 wt. %, based on the mesomorphic phase of edible surfactant and water.
Another preferred element of the present invention is the presence of bulk regions of mesomorphic phases in food products. Most preferred is the presence of bulk regions of mesomorphic lamellar phases. Bulk phases preferably consist of either a more or less continuous mesomorphic phase or of discrete particles of mesomorphic phase, for example having a number average particle size of between 1 fm and 1,000 fm. In this respect it should be noted that it has been suggested that known products of the prior art might contain non-bulk boundary layers of the lamellar phase at o/w interfaces, such as those found around oil droplets in water-continuous fatty products. The bulk regions of mesomorphic phase of edible surfactants may advantageously be used for replacing the aqueous phase and/or oil phase in food products in accordance to the invention.
Preferably food products in accordance to the invention contain at least 5% by volume of mesomorphic phase of edible surfactant, more preferred 10-100% by volume, for example 20-80% by volume, whereby the volume of the mesomorphic phase refers to the volume of the combined water/edible surfactant system.
According to the present invention any edible surfactant may be used although lipidic substances are preferred. However, the use of other, non lipidic surfactants, for example surfactant or amphiphylic carbohydrates is not excluded. In general the preferred edible surfactants are selected from the group consisting of nonionic surfactants, anionic surfactants and cationic surfactants.
Preferred non-ionic surfactants are edible monoglycerides, diglycerides, poly-glycerol esters, non-ionic phospholipids, non-fatty carboxylic acid esters of fatty acid esters, partial sugar-fatty acid esters and, partial fatty acid esters of polyols and mixtures thereof.
Preferred cationic surfactants are cationic phospholipids, cationic non-fatty carboxylic acid esters of fatty acid esters and mixtures thereof.
Preferred anionic surfactants are lactylated fatty acid salts, anionic phospholipids, anionic non-fatty carboxylic acid esters of fatty acid esters and their metal salts, fatty acids and their metal salts and mixtures thereof.
The fatty acid chains used in these surfactants can be of any type and origin. Preferably, however C8-28 fatty acid chains are present, more preferred C12-22, for example C14-18. The fatty acids may for example be saturated, unsaturated, fractionated or hydrogenated and be derived from natural (for example dairy, vegetable or animal) source or synthetic sources.
In another aspect the present invention relates to a finished foodstuff containing a mesomorphic phase of edible surfactant. For the purpose of the present invention, finished foodstuffs are food-products which are intended to be eaten without significant further processing. Excluded by this term are batters, doughs etc. Included are spreads, dressings, cheese, whippable products, ice-cream etc. Finished food products are generally marketed while packed in containers having a content of from 5 to 5,000 grams, more general 50 to 1,000 grams.
While foodstuffs according to the present invention can comprise a mesomorphic phase comprising 99-5 wt. % of water, it is preferred that the mesomorphic phase comprises 98-60 wt. % and in particular 97-80 wt. % of water, the percentages being based on the total weight of the mesomorphic phase. The total water level of products of the invention may for example be up to 99%, for example 10-90%, conveniently 20-80%.
Preferably the total level of edible surfactants in food products of the invention is from 0.1 to 30%, more preferred 1-15%, most preferred 2-10% by weight of the foodstuff.
Typical embodiments of the invention as illustrated hereafter by example comprise as the mesomorphic phase, in particular the bulk mesomorphic phase a combination of a major amount of a non-ionic surfactant and a minor amount of an ionic co-surfactant. Preferably, the mesomorphic phase comprises 1-30%, more preferred 2-10 wt. % of non-ionic surfactant for example monoglycerides and 0.005-10% more preferred 0.01-1 wt. % of ionic co-surfactant for example an alkali metal salt of a lactylated fatty acid, preferably sodium stearoyl lactylate the percentages being based on the total weight of the mesomorphic phase.
The presence of xe2x80x9cnon-ionicxe2x80x9d, xe2x80x9ccationicxe2x80x9d and xe2x80x9canionicxe2x80x9d surfactants is of course dependent on the pH-value of the foodstuff in which the surfactants are used. In this respect it should be noted that normally the pH for foodstuffs is between 3-8, for dairy products the pH-value is in the range of 4-7.
The combination of non-ionic and ionic surfactants is preferred because the ionic surfactants are believed to give rise to an electrical charge at the interface of the mesomorphic structure used according to the present invention. The mutual repulsion at the interface of surfactant and water in the mesomorphic phase, for example the lipid bi-layers in a mesomorphic lamellar structure, creates a layer structure in which a surprisingly large amount of water can be incorporated. This phenomenon allows for the use as edible fat replacer and water retention agent as attractive applications.
Preferably the nonionic surfactant and the ionic surfactant are used in weight ratios of from 100:1 to 1:10, more preferred 50:1 to 1:1, for example 40:1 to 10:1.
Preferred non-ionic surfactants are monoglycerides, lactylated esters of monoglycerides and phospholipids. Preferred ionic co-surfactants are alkali-metal salts of lactylated fatty acids, e.g. sodium stearoyl lactylate (SSL), citric acid ester, ionic phospholipids (phosphatidic acid (PA), succinated esters and diacetyl tartaric acid ester of monoglyceride (DATEM).
Especially in the presence of the alkali metal salt of a lactylated fatty acid, a monoglyceride-based mesomorphic system can take up a large quantity of water into the inter-planar water layers, and this xe2x80x98swellingxe2x80x99 of the emulsion improves suitability of the products as edible fat replacers. While the invention will be illustrated hereafter by reference to examples in which the surfactant system comprises both monoglyceride and SSL, the use of other, single surfactants or preferably combinations of two or more surfactants to obtain a swellable mesomorphic system is not hereby excluded.
While foodstuffs according to the invention generally will comprise less than 80% by weight of fat, the preferred level of this ingredient is 0-79 wt. % fat, for example 0 to 40%, preferably 1-30%. In some products a low fat content may be required as a flavour carrier.
Suprisingly it has also been found that the mesomorphic phase, which is used according to the invention, can be used in foodstuffs containing electrolyte, without affecting the structuring capability of the system. One example of electrolytes that may be incorporated is sodium chloride. The amount of electrolytes such as salt in foodstuffs according to the invention preferably ranges from about 0.01-5 wt. %, more preferred 0.1 to 3%, for example 0.2 to 2% based on the total weight of the finished food product.
The mesomorphic phases of edible surfactants, which are used according to the present invention, can be used in foodstuffs containing a bio-polymer such as carbohydrates e.g. pectins, rice starch, other starches and carrageenan, or proteins. Suitable materials are for example milk protein, gelatin, soy protein, xanthan gum, locust bean gum, agar, hydrolysed starches (for example PaselliSA2 and N-oil), microcrystalline cellulose. Especially preferred is the use of these biopolymer materials in spreads according to the invention.
The amount of biopolymer in compositions of the invention is dependant on the desired degree of gelling and the presence of other ingredients in the composition. Usually the amount of gelling agent lies between 0 and 30%, mostly between 0.1 and 25% based on the weight of the aqueous phase of the product. If hydrolysed starches are present their level is preferably from 5-20%; other gelling agents are generally used at levels of up to 10%, mostly 1-7%, most preferred 2-5% all percentages being based on the weight of the aqueous phase. Particularly preferred are combinations of say 5-15% hydrolysed starch and 0.5-5% of other gelling materials. Preferably the other gelling material includes gelatin.
It is preferable that fat and mesophase containing foodstuffs should comprise less than 10% saturated fat or equivalent thereof on produce and/or less than 10% trans fat or equivalent thereof on product. Embodiments of the invention include sunflower oil based spreads which contain no added xe2x80x98hardstockxe2x80x99 components. These xe2x80x98hardstockxe2x80x99 components include saturated fats and trans fats of which the overall dietary intake should be reduced.
Examples of foodstuffs in which the mesomorphic phases of edible surfactants may be used, are spreads, in particular zero- or extremely low fat spreads (which contain less than about 20% of fat), dressings, i.e. spoonable or pourable dressings e.g. dressings of the mayonnaise-type, dairy and non-dairy creams, toppings, processed cheese, semi-hard cheese, sauces, sweet spread, pastry-margarines, whippable products, sauces, liquid dairy products and ice cream.
For preparing food-products containing the mesomorphic phase in accordance with the invention, it is possible to prepare the mesomorphic phase separately and add this phase as an ingredient to the other ingredients of the product, or it is possible to prepare the mesomorphic phase xe2x80x9cin-situxe2x80x9d in the presence of one or more other ingredients of the composition. In any case, however, the preparation of the mesomorphic phase preferably takes place while heating to a temperature above the Krafft temperature, followed by cooling. Generally these temperatures are from 0-100xc2x0 C., more general 30-90xc2x0 C., most general 40-70xc2x0 C. Any heat- sensitive ingredients or ingredients which could prevent the formation of a mesomorphic phase are preferably added after cooling.
The invention will be further illustrated by means of a number of specific embodiments: it will be evident that the scope of the invention is not limited to these specific embodiments.
I. Dressings or Mayonnaise
A first embodiment of the present invention relates to dressings containing a mesomorphic phase of edible surfactants. Suitable uses are as structuring agent, fat replacer, egg replacer, preservative, lubricating agent, consistency control agent, moisture retention agent and flavour release agent. Especially preferred is their use in dressings as a fat replacer, egg replacer and consistency control agent.
Generally dressings or mayonnaise are oil in water emulsions. The oil phase of the emulsion generally is 0 to 80% by weight of the product. For non-fat reduced products the level of triglycerides is generally from 60-80%, more preferred from 65-75% by weight. For salad dressings the level of fat is generally from 10-60%, more preferred from 15 to 40%. Low or no-fat containing dressings may for example contain triglyceride levels of 0, 5, 10 or 15% by weight.
Other fatty materials such as for example polyol fatty acids ester may be used as a replacement for part or all of the triglyceride materials.
The level of edible surfactant material in the dressing will generally be from 0.1 to 15%, more preferred from 2-10%, most preferred from 1 to 8% by weight. Preferably the level of nonionic edible surfactant is from 0.1 to 15%, more preferred, 0.5-10%, most preferred 1 to 8% by weight. Especially preferred are monoglycerides as nonionic edible surfactants. Preferably the level of ionic edible surfactant is form 0 to 5%, more preferred to 0.05 to 2%, most preferred 0.1 to 0.5% by weight.
Dressings are in general low pH products with a preferred pH of from 2-6, more preferred 3-5, for example about 3.5. The use of ionic surfactants is at these pH values is limited to a number of compounds, because proper functioning of the ionic surfactant requires that the surfactant molecule is at least partly dissociated at the indicated pH. For the use in dressings the preferred anionic is the diacetyl tartaric ester of monoglycerides (In the examples Admul DATEM 1935 ex. Quest Int. has been used). Also an anionic phospholipid such as phophatidic acid can be applied.
In addition to the above mentioned ingredients dressings in accordance to the present invention optionally may contain one or more of other ingredients which may suitably be incorporated into dressings and/or mayonnaise. Examples of these materials are emulsifiers, for example egg-yolk or derivatives thereof, stabilisers, acidifiers, biopolymers, for example hydrolysed starches and/or gums or gelatin, bulking agents, flavours, colouring agents etc. The balance of the composition is water, which could advantageously be incorporated at levels of from 0.1-99.9%, more preferred 20-99%, most preferred 50 to 98% by weight.
The mesomorphic phase of edible surfactant in the mayonnaise of dressing may either be prepared separately before adding the other ingredients of the composition, or may be formed xe2x80x9cin-situ,xe2x80x9d in the presence of other ingredients. As described above, an important aspect of the formation of a mesomorphic phase of edible surfactants is the heating of the edible surfactant and water to a temperature above the Krafft temperature of the surfactant. Hence it is preferred that any ingredients of the dressing or mayonnaise that would not be resistant to these elevated temperatures and/or could present the formation of the mesomorphic phase, are added after the mesomorphic phase of edible surfactant has been formed.
A preferred process for the preparation of dressings and mayonnaise therefore comprises the following steps:
(a) heating a mixture containing water, edible surfactant and optionally other ingredients to a temperature above the Krafft temperature of the edible surfactant;
(b) cooling the mesomorphic phase and adding the remaining ingredients of the composition.
During this process it is generally preferred that at some stage the ingredients are mixed under such conditions that the required structure can be formed. Such a mixing can usually take place under moderate shear.
II. Spreads
Another preferred embodiment of the invention is the use of mesomorphic phases of edible surfactants, as generally specified in the above, in spreads. Suitable uses are as structuring agent, fat replacer, egg replacer, preservative, lubricating agent, consistency control agent, moisture retention agent and flavour release agent. Especially preferred is their use in spreads as a fat replacer, flavour release agent, consistency control agent or preservative.
Spreads according to the embodiment generally contain from less that 80% by weight of edible triglyceride materials. Suitable edible triglyceride materials are for example disclosed in Bailey""s Industrial Oil and Fat Products, 1979. In spreads of non-reduced fat content (margarines), the level of triglyceride material will generally be more than 60% and less than 80%, preferably from 70 to 79% by weight. In spreads of reduced fat content the level of triglycerides will generally be from 30-60%, more general from 35 to 45% by weight. In very low fat spreads the level of triglycerides will generally be from 0-40%, for example 30%, 25%, 20% or even 10% or about 0%. Other fatty materials, for example sucrose fatty acid polyesters may be used as a replacement for part or all of the triglyceride material.
The edible surfactant material for use in spreads is preferably used at a level of from 0.1 to 15%, more preferred from 1-10%, most preferred from 2 to 8% by weight. Preferably the level of nonionic edible surfactant is from 0.1 to 15%, most preferred, 1-10%, most preferred, 2 to 8% by weight. Especially preferred are monoglycerides and lecithins as nonionic edible surfactants. Preferably the level of ionic edible surfactant is from 0 to 5%, more preferred 0.05 to 2%, most preferred 0.1 to 0.5%. Preferred ionic edible surfactants are lactylated fatty acid salts and phophatidic acid.
Monoglycerides for use in spreads are preferably freshly made so as to have a good taste.
In accordance to the above mentioned ingredients, spreads in accordance with the invention may optionally contain further ingredients suitable for use in spreads. Examples of these materials are gelling agents, sugar or other sweetener materials, EDTA, spices, salt, bulking agents, flavouring materials, colouring materials, proteins, acids etc. Particularly preferred is the incorporation of biopolymers in spreads. Suitable biopolymer materials are for example milk protein, gelatin, soy protein, xanthan gum, locust bean gum, hydrolysed starches (for example PaselliSA2 and N-oil), rice starch and microcrystalline cellulose.
The amount of biopolymer in spreads of the invention is dependant on the desired degree of gelling and the presence of other ingredients in the composition. Usually the amount of gelling agent lies between 0 and 30%, mostly between 0.1 and 25% based on the weight of the aqueous phase of the spread. If hydrolyzed starches are present their level is preferably from 5-20%; other gelling agents are generally used at levels of up to 10%, mostly 1-7%, most preferred 2-5% all percentages being based on the weight of the aqueous phase. Particularly preferred are combination of say 5-15% hydrolysed starch and 0.5-5% of other gelling materials. Preferably the other gelling material includes gelatin.
The balance of the composition is generally water, which may be incorporated at levels of up to 99.9% by weight, more general from 10 to 98%, preferably from 20 to 97% by weight. Spreads according to the invention may be fat and/or water continuous.
The mesomorphic phase can be used as a partial or entire replacement for the water phase and/or oil phase in the spread products.
In the preparation of spreads in accordance with the invention, the mesomorphic phase may either prepared before the addition of other ingredients or the mesomorphic phase may be prepared xe2x80x9cin-situxe2x80x9d while other ingredients of the composition are present. In any case however, the formation of the mesomorphic phase, preferably involves the heating of the edible surfactants and water to a temperature above the Krafft temperature. Therefore, heat-sensitive ingredients or ingredients which could prevent the formation of mesomorphic phase, should preferably be added after the formation of the mesomorphic phase.
In general the method for preparing spreads according to the invention involves the mixing of the edible surfactants (preferably a mixture of a non-ionic surfactant and a co-surfactant) and water to a temperature just above the Krafft-temperature of the system. Other ingredients, e.g. salt, colouring agents and flavouring ingredients can also be added. The pH can be set to the desired value using e.g. sodium hydroxide or lactic acid. This mixture is then stirred gently until the components are distributed homogeneously. Subsequently the formed mesomorphic phase is cooled down, generally while applying shear. This results in a low calorie plastic spreadlike gel phase with oral properties similar to high- and reduced fat spreads. The fat ingredient of the spread, if any, is preferably added after cooling and mixed into the product under stirring to effect the desired structure formation. Sweet spreads may be prepared accordingly.
Where gel-forming ingredients in addition to the mesomorphic phase are to be used it may be advantageous to prepare the spread using a split stream process in which a xe2x80x9cfilled gelxe2x80x9d is ultimately formed. In a filled gel split stream process, the mesomorphic phase is formed in one stream and a phase including gelled particles is formed in a second stream, after which the two streams are combined. The gelled particles maintain their individual gelled structures after combination with the mesomorphic phase so that the gelled particles in the second stream become embedded in and xe2x80x9cfillxe2x80x9d the gelled mesomorphic phase.
A filled gel may also be formed by adding gel particles to the surfactant and other ingredients prior to the formation of the mesomorphic phase if the gelled particles are formed from heat-stable gels. For instance, a slurry of gel particles made from heat stable gels such as agar or certain pectins could be added to the ingredients from which the mesomorphic phase is to be formed and the mixture heated and then cooled to form the mesomorphic phase. Provided that the temperature used does not exceed the maximum temperature at which the heat stable gelling agents form gels, the gelled particles retain their identity and a filled gel is obtained.
It has been found that filled gels are advantageously used to form spreads having a minimal amount of surfactant, e.g., less than about 3%, especially down to levels of around, e.g., 1.5%. Thus, where the surfactant is a fatty substance such as a monoglyceride, use of filled gels permit an even further decrease in the fat level. Preferably, the gelled particles are from 1-100 microns, especially from about 10 to about 50 microns.
III Whippable Products Such as Creams
Another preferred embodiment of the invention is the use of mesomorphic phases of edible surfactants in whippable products, in particular whippable non-dairy creams, mousses, bavarois, etc. Preferred uses are as foam control agent and fat replacer.
Preferably the level of edible surfactant in whippable dairy products is from 0.1 to 30% by weight, more preferred 1 to 20%, most preferred 2 to 15% by weight of the composition. Preferably the edible surfactant material comprises nonionic surfactants such as monoglycerides, for example at levels of 0.1 to 30%, more preferred to 1 to 20%, most preferred 2-15% by weight. In addition to the monoglyceride co-surfactants may be present, for example at a level of 0 to 10%, more preferred 0.1 to 8%. A preferred cosurfactant is lecithin.
In addition to the edible surfactant materials in the mesomorphic phase, whippable products in accordance to the invention may advantageously contain one or more other ingredients, for example proteins, sugar, emulsifiers, colorants, flavouring agents, fat (preferably vegetable fat), skimmed milk ingredients, biopolymers etc. For example the fat level may be less than 80%, more preferred 0-40%, for example about 5%, 15% or 30%. The balance of the composition is preferably water.
As described above the mesomorphic phase of edible surfactants may be prepared before mixing the remaining ingredients or may be formed in-situ in the presence of one or more other ingredients of the composition. In any case, however, the formation of the mesomorphic phase preferably takes place while heating above the Krafft temperature of the system, followed by cooling. Heat sensitive ingredients or ingredients which could hamper the formation of a mesomorphic phase are hence preferably added after formation of the mesomorphic phase.
A convenient process for the preparation of a whippable product in accordance with the invention involves therefore the heating of the edible surfactant and the water to a temperature above the Krafft temperature under gentle stirring followed by cooling and adding the remaining ingredients. Excessive stirring should sometimes be avoided after cooling, to prevent undesired air incorporation in the product in an unwhipped state.
IV Ice Cream or Other Frozen Deserts
A further advantageous embodiment of the present invention relates to the use of mesomorphic phases of edible surfactants in frozen desserts. Suitable uses are as structuring agent, fat replacer, preservative, lubricating agent, consistency control agent, foaming agent, moisture retention agent and flavour release agent. Especially preferred is their use in frozen desserts of ice cream as a structuring agent, foaming agent, fat replacer or for improving melt-down properties.
Problems often encountered while using conventional fat-replacers in frozen desserts are off-flavours and difficulties in suitably controlling the structure and eating characteristics. It has been found that while using the mesomorphic phases of edible surfactants, frozen desserts can be obtained having the structure and sensoric properties of ice cream but a lesser caloric content. Also fat-free ice-cream like products can be obtained. Furthermore the use of mesomorphic phases of edible surfactants can provide frozen desserts having improved melt-down properties.
Although by using the mesomorphic phase concept an ice-cream impression can be achieved without any fat, it may for some flavours be convenient to use a relatively small amount of fat (e.g. up to 2 to 3% by weight, preferably 0.5 to 1% by weight) for improving the flavour release. Needless to say that the calorific content increases by this addition.
Preferred frozen dessert compositions contain up to 10%, for example from 0.1 to 6% of edible surfactant, more preferred from 0.3 to 5%, most preferred from 0.5 to 2% by weight. Preferably the level of non-ionic edible surfactants is up to 10%, for example from 0.5 to 5%, more preferred from 0.6 to 3%, most preferred from 0.8 to 1.5% by weight. Most preferred is the use of monoglycerides as the nonionic edible surfactant. Preferably the level of ionic edible surfactants is from 0 to 1%, more preferred 0.05 to 0.5% by weight. Preferred ionic edible surfactants are lactylated fatty acids.
In addition to the mesomorphic phases of edible surfactants, frozen desserts of the present invention may contain all conventional ingredients suitable for incorporation therein. For example, frozen desserts according to the present invention will usually contain one or more ingredients for improving the sweetness thereof. Preferably sugar is used as the sweetening material. If sugar is used as sweetening agent, the level thereof is preferably from 5-40%, more preferred 10-20%. If other sweetener materials such as for example aspartame (trademark) are used, the level of these materials is chosen such that the sweetness of the product resembles that of a product having the above mentioned sugar contents. Use of artificial sweetener materials may further require the use of one or more bulking agents, for example hydrogenated starch materials.
Furthermore frozen desserts according to the invention preferably contain milk solids non fat (MSNF) at levels of 1-20%, more preferred 6-14% by weight. Additionally frozen desserts may advantageously contain low levels of emulsifier and/or stabilising agents, for example at a level of 0 to 0.5%, more preferred 0.2 to 0.4% by weight. Optionally further ingredients suitable for incorporation in frozen desserts may be used, for example fruit, flavours, colouring agents, chocolate, nuts, preservatives, biopolymers and freezing point depressants. Generally the balance of the composition will be water.
Suitable recipes resulting in improved melt-down properties are for example as follows:
0.5-5% monoglyceride, preferred 0.8-1.5%
0-1% ionic surfactant, preferred 0.05-0.5%
10-20% sugars,
6-14% milk solids non fat (msnf)
0-0.5% emulsifiers and stabiliser.
The balance being water and usual additives for frozen desserts. In these recipes, as usual, the sugars are contained both as sweeteners, freezing point depressants and as texturizing agents. As usual these purposes may be achieved by different means, e.g. using sucrose in combination with invert sugar, fructose, glucose, maltodextrin, corn syrups. A preferred sugar combination in the above recipes being 5-8% maltodextrin and 9-14% sucrose.
The same applies to the milk solids non fat: about one third thereof can be whey powder, so a suitable msnf combination in the above recipes is 6-8% msnf (including casein) and 1-3% whey powder.
Emulsifiers and stabilizers can be used as usual and examples thereof are widely known. Suitable amounts and products are exemplified in the examples. A preferred range for the total amount of these additives is from 0.2 to 0.4%.
Frozen desserts according to the invention may be prepared by any conventional method for the preparation of ice-cream and the like. For formation of the mesomorphic phase preferably the edible surfactant in the presence of water and optionally one or more further ingredients of the composition is heated to a temperature above the Krafft temperature of the mixture, followed by cooling down, addition of the remaining ingredient and stirring under further cooling to obtain an aerated frozen dessert.
Conveniently the mesomorphic phase can be formed in-situ by mixing of the ingredients (preferably at an elevated temperature of 60-100xc2x0 C., for example 70-95xc2x0 C.)., followed by the cooling down (to a temperature of 0-30xc2x0 C. say about 5xc2x0 C.) and homogenation, whereafter after an optional aging step (up to say 24 hours) the mixture is preferably whipped to have an overrun of between 50 and 300%, more preferred 75-200%, most preferred about 100%, while cooling in a usual continuous ice cream freezer to a low temperature (say 0 to xe2x88x9220xc2x0 C., more preferred xe2x88x922 to xe2x88x9210xc2x0 C., most preferred about xe2x88x925xc2x0 C.) and storage a temperature of say xe2x88x9210 to xe2x88x9230xc2x0 C. Alternatively the mesomorphic phase can be prepared separately, and the other ingredients can be added to the phase afterwards, whereafter the product is aerated and cooled.
V. cheese
Another preferred embodiment of the invention relates to the use of mesomorphic phases of edible surfactants in cheese products, for example processed cheese or semi-hard cheese. Preferred uses for the mesomorphic phase in cheese products are is structuring agent, fat replacer, lubricating agent, preservative, consistency improving agent and moisture retention agent.
Cheese products in general often contain dispersed droplets of fat dispersed in a matrix, which is often structured by casein. For the purpose of the present invention the mesomorphic phase may be used for replacing part or all of the dispersed phase, but also possible is that the mesomorphic phase is used as a replacement for all or part of the cheese matrix. In the former case, the mesomorphic phase will be present as a bulk phase consisting of discrete particles of the mesomorphic phase. In the latter case the mesomorphic phase may be a continuous bulk phase or may consist of discrete particles.
Preferably the level of edible surfactant in the cheese product will be from 0.1 to 15% by weight of the composition, more preferred 0.5 to 10%, most preferred 1 to 8%. Preferably the level of nonionic surfactant is from 0.1 to 15%, more preferred 0.5 to 10%. The level of ionic surfactants is preferably from 0 to 7%, more preferred 0.1 to 5%.
In addition to the mesomorphic phase of edible surfactant, cheese products of the invention may advantageously contain all types of ingredients which can be present in cheese, products. Examples of these ingredients are milk protein (preferably present at a level of 0-15%, more preferred 0.5 to 10%), fat (preferably present at levels from 0-45%, more preferred 1-30%); other fatty materials such as for example polyol fatty acid esters can replace all or parts of the fat, electrolytes (for example CaCl2 and/or NaCl at levels of 0 to 5%, more preferred 1-4%), rennet or rennin (for example at a level of 0.005 to 2%, more preferred 0.01-0.5%), flavours, coloring agents, emulsifiers, stabilisers, preservatives, pH adjusting agents, biopolymers etc. The balance of the product is generally water which may be present at levels of for example 0-99.5%, more preferred 5-80%, more preferred 30-75% by weight).
The cheese products according to the present invention range from soft cheeses to hard cheeses of various types such as semi hard cheeses (such as Gouda, Edam, Tilsit, Limburg, Lancashire etc), hard cheeses (for example Cheddar, Gruyer, Parmesan), external mould cheeses (e.g., Camembert and Brie), internal moulded cheeses (e.g. Roquefort, Corgonzola etc), processed cheeses and soft cheeses (cottage cheese, cream cheese, Neufchatel etc.).
The cheese products of the invention maybe prepared by any suitable process for the preparation of cheeses. Although this is dependant on the type of cheese, generally the following stages may be present: (1) mixing the ingredients at a suitable temperature, for example at 5-120xc2x0 C.; (2) After cooling addition of a starter culture, cutting of the curd, moulding and eventual salting; and (2) ripening. As indicated above the mesomorphic phase of edible surfactants maybe formed separately or may be formed xe2x80x9cin-situ.xe2x80x9d If the mesomorphic phase is prepared separately, the phase thus formed is preferably added to the other ingredients in stage (1) as described above. If in-situ formation of the mesomorphic phase is used, this is preferably effected by addition of the edible surfactant to the mixture in stage 1, and ensuring that the temperature of the mix is elevated to above the Krafft temperature.
IV. Other food products
Other food products in accordance with the invention which could advantageously contain a mesomorphic phase of edible surfactants, involve other edible emulsified systems, sauces, liquid and semi liquid dairy products, bakery cream, topping etc.